Nodes in a communications network such as an optical network may typically comprise an administrative node processor module (ANPM) and a persistent storage module (PSM). The processor module comprises a processor and a primary database. The administrative node processor module is concerned with control of administrative functions, examples of which include configuring and monitoring elements of a node and providing a management interface to a user.
The persistent storage module (PSM) typically comprises a memory access unit, for example a file server, and maintains a backup database of administrative information for the node. Persistence means that the stored information has to continue to exist even after one or more applications that saved and manipulated the data have ceased to run. Examples of administrative information are the default states and/or current states of the elements or components of the node. Examples of information stored would be power settings, and states of switches and indicators.
According to one method of providing fault tolerance in telecommunications systems, a database manager of the administrative node processor module transfers information to the persistent storage module to maintain a mirrored copy of its database. For example, if the processor module fails, upon replacement, the new processor module will query the persistent storage module and reconstruct a mirrored copy of the database thereby allowing hotswapping of the processor module.
While this mirroring technique is a standard solution for fault tolerance in telecommunications systems, it is generally desirable to decrease the costs of a system by requiring less hardware.
Therefore, in a network, it would be desirable if every node did not require its own persistent storage module. It would also be desirable if every node did not require its own administrative node processor module, which would further reduce hardware costs.